Method and device for the display of images from a group of images

ABSTRACT

For the display of images, notably X-ray images, the complete image of full resolution, usually consisting of a group of images, may be substantially larger than the size that can be reproduced on a display screen. In accordance with the invention, the overall group of images is displayed on the display screen as an auxiliary image in a strongly reduced scale, the size of the auxiliary image being dependent on the group of images. Via a frame which is reproduced in the auxiliary image and whose dimensions and position can be varied, a part of the group of images, i.e. one image or separate neighboring images, is selected and displayed on the overall display screen. When the frame is shifted in the auxiliary image, the part of the overall group of images which is displayed on the display screen is also automatically shifted. The images reproduced in the auxiliary image can be shifted and modified, for example rotated or enlarged or reduced, and any modification of an image situated within the frame is reproduced directly on the overall display screen. The overall view of the entire group of images is thus always preserved.

The invention relates to the display of one or more neighboring imagesor sub-groups of images as a part of a larger group of images wherefromthe image or images to be displayed can be selected.

A need for such a type of display exists, for example in the medicalfield, notably if a selection of images from among a plurality of X-rayimages showing, for example the development of a diseased area of apatient over a given period of time, is to be reproduced more clearly,i.e. with an increase in scale. Basically, it is not problematic toselect a single image or several neighboring images from a plurality ofimages and to display these images completely on a display screen or, inthe case of a single large image instead of the group of images, to zoomor enlarge a detail, notably if the image data for the group of imagesor the large image enable a high resolution. However, once the selectedor enlarged display has been realized, the overall view of the group ofimages or the large image will be lost and in order to regain thisoverall view, the entire group of images or the large image should thenbe displayed again in order to enable individual images or a part to beselected therefrom again. This is very unattractive with a view to easeof operation.

It is an object of the invention to provide a method and a device whichenable individual images or sub-groups of images or a part of an imageto be selected simply and distinctly from a group of images, which mayalso consist of one large image, and also enable a fast and distinctchange over to other images or sub-groups of images or parts of animage.

This object is achieved according to the invention by means of themethod disclosed in claim 1 and the device disclosed in claim 6.

Thus, an auxiliary image which occupies only a small part of the screensurface area is displayed on the display screen and the entire group ofimages, or the large image, is reproduced in the auxiliary image at astrongly reduced scale. This auxiliary image is permanently preserved,thus occupying a small part of the display screen or one display screen,but the overall view of the entire group of images is thus permanentlymaintained. The size of the auxiliary image is dependent on themagnitude, i.e. the size of the group of images. When additional imagesare included in the group of images, the auxiliary image will becomelarger because the scale of reduction is effectively maintainedconstant. A frame is reproduced in the auxiliary image and the partwhich is situated within a frame reproduced in the auxiliary image isdisplayed completely on the display screen, be it that a small partthereof is masked by the auxiliary image. The position and thedimensions of the frame reproduced can be shifted and enlarged orreduced, respectively, via a keyboard or a so-called mouse, and the partof the auxiliary image which is situated within the frame is alwaysautomatically displayed on the display screen. The auxiliary imageconstitutes as if it were a virtual display screen wherefrom the realdisplay screen is automatically selected by the frame. Because of thepermanent display of the auxiliary image, however, the overall view ofthe entire group of images or the large image will be preserved.

It is to be noted that use can also be made of a plurality of closelyadjacent display screens which together constitute a logic displaysurface, different parts of the image to be displayed then beingreproduced on different display screens. The auxiliary image is thendisplayed on one of the display screens only. The window reproduced inthe auxiliary image may also contain a plurality of images or sub-groupsof images; in this case preferably one of the images contained in thewindow, or one of the sub-groups of images, is displayed on each of theplurality of display screens.

Preferably, the magnitude of the group of images wherefrom the part isselected can be changed by including further images or sub-groups or byerasing images present. The size of the auxiliary image then changesaccordingly, so that the auxiliary image will always be only as large asnecessary for the overall group of images. The inclusion of additionalimages or sub-groups does not change the display of the instantaneouslydisplayed frame and the partial image on the display screen. Merelyfurther memory locations of the memory directly associated with thedisplay screen are filled with the additional reduced images or imageareas.

The dimensions and the position of the frame are changed, for example byactuation of keys of a keyboard or via a so-called mouse. The positionand the dimensions of the frame in the auxiliary image can in principlebe chosen at random. For ease of operation, notably to enable fast andaccurate selection of one or more neighboring images, the dimensions ofthe frame and its position can preferably be changed only in given,rather large steps which comprise a plurality of pixels. The adjustmentof the frame to, for example a given image is thus facilitated.

The image or the group of images is always present with a given, highresolution which is strongly reduced for the reproduction in theauxiliary image. This image reduction is preferably performed byaveraging over image data of a number of neighboring pixels. Thus, theimage is displayed on the display screen with a resolution which isequal to or lower than that of the image, depending on the dimensions ofthe frame in the auxiliary image. Enlarged reproduction may also bedesirable in case the frame is chosen to be very small. In the case of aslight reduction, for example weighted averaging over neighboring pixelsmay be performed, whereas enlargement can be realized by a giveninterpolation.

When the image or the sub-group of images to be displayed is selectedfrom a group of images reproduced in the auxiliary image, the images arereproduced in the auxiliary image according to a given order which isdependent on properties or attributes of the sub-images. For example,X-ray images of different parts of the body of a patient may be orderedaccording to the individual body parts. Upon evaluation of the images bya physician, however, it may appear that a different order is moreeffective, for example an order of the images according to age.Therefore, the order and/or the reproduction of images in the auxiliaryimage can preferably be selected by third control instructions entered.The physician evaluating the images can then easily modify the order ofthe images in the auxiliary image if this appears to be necessary duringevaluation. Furthermore, images in the auxiliary image can preferably beshifted by means of control instructions applied notably via a mouse.For example, an image can thus be shifted into the area enclosed by theframe reproduced, so that it is automatically displayed. Thispossibility is particularly attractive if one or more sub-groups ofimages are situated within the frame and individual images are movedindependently of one another, in which case the sub-group need notalways be completely filled with the images. In addition to thepossibility of shifting, individual images of the images reproduced inthe auxiliary image themselves can preferably be changed, for example byenlargement or reduction, changing of the orientation, i.e. rotation,mirroring, or also in respect of halftone reproduction in that smallhalftone differences in given halftone ranges are increased. Such imagemanipulations are known in principle. In the context of the presentinvention Such manipulations can be applied to the images in theauxiliary image, each such manipulation also appearing automatically inthe images reproduced full size on the entire display screen or thedisplay screens, or, conversely, can be applied directly to theseimages, the corresponding images in the auxiliary image then beingchanged in the same way.

The invention also relates to a device for the display of images from agroup of images, including at least one display screen, a first memoryfor the image data to be displayed, a control unit for converting thisdata into image control signals, a second memory for storing the data ofthe entire group of images, and a processing device which transfers theimage from the second memory to the first memory in reduced form andprocesses the frame data entered.

Embodiments of the invention will be described in detail hereinafterwith reference to the drawing. Therein:

FIG. 1 shows a block diagram of a device according to the invention, and

FIG. 2 illustrates the display of the image and the auxiliary image withthe frame on a display screen.

FIG. 1 shows two adjacently arranged display screens 1 and 2 whichtogether constitute a logic display surface on which images (not shown)and an auxiliary image 4 are displayed. The display screens 1 and 2receive the data for the image to be displayed, via the connection 3,from a control unit 6 which receives image data from an image memory 8,via the connection 5, and converts this data into drive signals on theconnection 3. Depending on the size of the individual images, one ormore images can be displayed on each of the display screens.

Via the connection 9, the image memory 8 receives the image datacorresponding to the image to be displayed with the auxiliary image froma processing unit 10 which communicates, via connections 11 and 13, witha second memory 12 which contains the image data of a group of images.Via the connection 15, the processing unit 10 also receives controlinstructions from an input unit 14, for example a keyboard or aso-called mouse or a combination thereof. In response to giveninstructions issued, the processing unit 10 addresses the memory 12, viathe connection 13, and reads its content via the connection 11. From theimage data read there is formed, preferably by averaging of data ofneighboring pixels, new image data for a reduced auxiliary image whichis applied, via the connection 9, to the image memory 8 in which it iswritten in given memory locations which correspond to the position ofthe auxiliary image 4 on the display screen 2. These memory locationsare determined by corresponding control instructions given via the inputdevice, so that the position of the auxiliary image 4 on the displayscreen 2 can be adjusted at random. The auxiliary image 4 is displayedon one of the display screens only.

Moreover, the processing unit 10 generates frame data for a window to bereproduced in the auxiliary image 4, which data is either written intothe image memory 8, via the connection 9, or applied to the control unit6, via the dashed connection 7, in order to enter this frame datadirectly into the auxiliary image displayed. The frame preferably has arectangular shape, like the display screens on which the images presentwithin the frame are displayed. The dimensions and the position of theframe within the auxiliary image can be changed by application ofcontrol instructions from the input unit 14 to the window data. Theimage data of the memory 12 which is associated with pixels within theframe is also converted into image data for the image memory 8 by theprocessing unit 10 and written into said image memory, i.e. at allmemory locations for the overall display screen 1, 2, with the exceptionof the memory locations for the auxiliary image 4. However, theprocessing unit can instead transfer all data for the image or sub-imageto be displayed on the display screen to the memory 8, after which thisdata is overwritten by the data for the auxiliary image 4.

The position of a point of the auxiliary image 4, for example the topleft-hand corner, on the display screen 2 is defined by controlinstructions applied to the processing unit 10 by the user, via theinput unit 14, whereas the size of the auxiliary image 4 is dependent onthe magnitude of the group of images stored in the memory 12. Viaappropriate control instructions from the input unit 14, further imagedata can be transferred from a bulk memory 18 to the memory 12 in orderto enlarge the overall group of images. The auxiliary image 4 on thedisplay screen is then also enlarged accordingly. It is also possible toerase images in the group of images, so that the auxiliary image 4becomes smaller.

The dimensions and the position of the frame in the auxiliary image 4can also be changed by way of control instructions from the input unit14. Accordingly other data, associated with other pixels, is then readfrom the memory 12, via the connection 11, and converted into image datafor the memory 8. The dimensions of the frame reproduced in theauxiliary image 4 are preferably chosen so that the corresponding imageor the corresponding images from the group of images in the memory 12are displayed with full resolution, the processing unit conducting theimage data received via the connection 11 directly to the memory 8 viathe connection 9. However, if the frame is chosen to be larger, the partof the auxiliary image which is defined thereby must be reproduced at areduced scale on the display screen 1, 2, because the dimensions of thedisplay screen do not change. This reduction is performed by averagingin the processing unit 10, preferably by weighted averaging of the datasupplied via the connection 11. In principle it is also possible toreduce the frame. In that case the part of the image must be reproducedin a scale which is larger than the value corresponding to the datastored in the memory 12, i.e. the processing unit 10 must generateadditional image data (preferably by interpolation).

A change of the order of the images in the group of images stored in thememory 12 relative to one another upon reproduction in the auxiliaryimage 4, or a shift of an image can be realized by transferring theimage data to the memory 12. However, it is alternatively possible forthe processing unit to recalculate merely the addresses via which thememory 12 is addressed, via the connection 13, so as to determinetherefrom the reduced reproduction of the entire group of images in theauxiliary image 4. These two possibilities exist in principle also ifone of the images of the group of images stored in the memory 12 must bereproduced at an enlarged or reduced scale, or when an image is to bereproduced in a mirrored fashion or with a changed or rotatedorientation. Modification of the halftone reproduction, notably anincrease of the halftone differences in an image, often requires arather complex calculation which may require an intermediate or buffermemory which is provided, for example in the processing device 10. Theappropriate control instructions for such image manipulations areentered via the input unit 14.

The processing unit 10 is preferably formed by a computer, the imagememory 8 then being formed by the main memory of the computer. Suchknown computers also include a control unit 6 for controlling at leastone display screen, so that the device shown in FIG. 1 can be formed bya universal computer, the memory 12 then being formed, for example, bythe hard disk memory of such a computer.

FIG. 2 illustrates the display of two images on the display screens 1,2. On the display screen 2 an auxiliary image 4 is reproduced as awindow which shows a complete group of images at a reduced scale. Thisauxiliary image is shown to be larger in FIG. 2 than it actually occursin practice. The auxiliary image 4 shows a group of images which issubdivided into six fields 21 to 26; for the sake of clarity only FIGS.30 to 33 are indicated in the fields 21 and 22, said figuresrepresenting the image content of two images in each field. Each field21 and 22 thus contains a sub-group consisting of two images, each withone figure which itself can be changed, shifted or otherwisemanipulated.

The sub-groups 21 and 22 are enclosed by a frame 20 which is reproducedon the display screen in a clearly visible manner, for example as a wideband or in color. The images or figures situated within this frame aredisplayed at an enlarged scale on the display screens 1 and 2, i.e. theFIG. 32 is displayed as the FIG. 32a on the display screen 1 and theFIG. 33 as the FIG. 33a. Similarly, the FIGS. 30 and 31 are displayed asthe FIGS. 30a and 31a on the display screen 2. The FIG. 30a is not showncompletely, because a small part of it is masked by the window 4.

The fields 21 to 26 do not completely fill the auxiliary image 4, sinceabove and to the right of the images there are provided menu areas 27and 28. Via a mark on the display screen, which can be moved across thedisplay screen in known manner by means of a mouse, a pair of fields canbe selected in the menu area 27. Manipulations can be performed on theimages situated in the fields thus selected, said manipulations beingselected from the menu area 28, for example by means of the mouse.Similarly, the frame 20 can also be shifted or in this case reduced inthe auxiliary image. When the window 20 is adjusted to the fields 23 and24, the figures contained in the associated images (not shown in FIG. 2for the sake of clarity) are displayed on the display screens 1 and 2.Because each of the FIGS. 30, 31 is associated with an image and can bemanipulated per se, the individual images can be selected and shifted,by means of the mouse, either in the auxiliary image 4 or in thelarge-size reproduction on the display screens; for example, the imagewith the FIG. 30 can be shifted out of the field 22, or the figure canbe rotated, mirrored or its scale or its halftones can be changed. Thevarious possibilities can be selected at least partly from the menu area28. Furthermore, it is also possible to erase images or sub-groups ofimages and to add new images, the auxiliary image 4 becoming smallerproportionally upon erasure of images whereas it will occupy acorrespondingly larger area on the display screen 2 in the case ofaddition of images.

Any change in the auxiliary image 4 and also any manipulation of animage becomes visible not only in the auxiliary image 4, but at the sametime also at full scale on the display screens 1 and 2. This enablesvery distinct display of individual images or sub-groups of images froma group of images and also their processing, because the auxiliary imageshows at all times which images from the group of images are displayedon the overall display screen 1, 2 and with which manipulations.

Direct processing of the images displayed on the overall display screen1, 2 is also possible; in that case the corresponding images in theauxiliary image, i.e. the images situated within the frame, are thenautomatically modified in the same way.

We claim:
 1. A method for the display of one or more neighboring imagesfrom a group of images on at least one display screen,the image data ofthe group of images being stored and displayed as an auxiliary image ata reduced scale factor on the display screen or on one of the displayscreens, the size of the auxiliary image being determined only by themagnitude of the group of images and the reduced scale factor inconformity with the image data stored for said group, a sub-display inthe form of a frame being reproduced within the auxiliary image, theposition and dimensions of said frame in the auxiliary image beingmodifiable by externally applied first control instructions, the part ofthe group of images which is situated within the frame in the auxiliaryimage always being displayed as the image on the display screen or thedisplay screens, with the exception of only the area of the auxiliaryimage, and the order and/or the reproduction of at least some images ofthe group of images being modifiable under the control of externallyapplied third control instructions, any modification of an image alsotaking place automatically in the auxiliary image and vice versa.
 2. Amethod as claimed in claim 1, characterized in that the the group ofimages can be altered by addition or erasure of images under the controlof externally applied second control instructions, the size of theauxiliary image being automatically determined by the magnitude of thealtered group of images and the reduced scale factor.
 3. A method asclaimed in claim 1, characterized in that the dimensions and/or theposition of the frame can be changed only in steps which comprise aplurality of pixels on the display screen.
 4. A method as claimed inclaim 1, characterized in that the image is displayed in reduced scaleor an increased scale, depending on the dimensions of the frame relativeto the auxiliary image and on the image data determining the resolutionof the group of images.
 5. A method for displaying one or more images ona logical display surface comprising:selecting a plurality of images forinclusion in a group of selected images from images present in one ormore image memories, said selection being responsive to input controlinstructions, displaying on the logical display surface as an auxiliaryimage said group of selected images at a reduced scale factor, the sizeof said auxiliary image being determined by the magnitude of said groupof selected images and the reduced scale factor, the position of saidauxiliary image being responsive to input control instructions,displaying within said auxiliary image a frame having a size andposition responsive to input control instructions, and displaying on thelogical display surface those image of said group of selected imagesthat are within said frame, said displaying at a scale factor determinedby the relation of the size of logical display surface, the size ofthose images of said group of selected images within said frame, and theresolution of the images.
 6. The method of claim 5 wherein said logicaldisplay surface comprises two display screens, and wherein saidauxiliary image is displayed on only one of said display screens.
 7. Themethod of claim 5 further comprisingshifting within said auxiliary imageone or more chosen images of said group of selected images, saidchoosing and shifting according to input control instructions, andshifting in a corresponding manner within the logical display surfacethose chosen images which were shifted in said auxiliary image in saidimmediately previous shifting step and which are also displayed on thelogical display surface.
 8. The method of claim 5 furthercomprisingshifting within the logical display surface one or more chosendisplayed images, said choosing and shifting according to input controlinstruction, and shifting in a corresponding manner within saidauxiliary image those chosen images which were shifted in saidimmediately previous shifting step.
 9. The method of claim 5 furthercomprisingperforming within said auxiliary image on one or more of theimages of said group of selected images one or more operations ofrotation, mirroring, scale changing, or halftone changing, saidperforming according to input control instructions, and performingcorresponding operations within the logical display surface on thoseimages which were subject to operations in said auxiliary image in saidimmediately previous performing step and which are also displayed on thelogical display surface.
 10. The method of claim 5 furthercomprisingperforming within the logical display surface on one or moreof the displayed images one or more operations of rotation, mirroring,scale changing, or halftone changing, said performing according to inputcontrol instruction, and performing corresponding operations within saidauxiliary image on those images which were subject to operations in saidimmediately previous performing step.
 11. The method of claim 5 furthercomprisingaltering said group of selected images by either addingadditional images selected from images present in the one or more imagememories to said group of selected images, or by erasing selected imagesfrom said group of selected images, said altering according to inputcontrol instructions, and displaying on the logical display surface saidaltered group of selected images as an altered auxiliary image having asize determined by the magnitude of the altered group of selected imagesand the reduced scale factor, wherein the display of said frame is notchanged.
 12. The method of claim 5 wherein said displaying said group ofselected images displays images from said group of selected images insaid auxiliary image in an order dependent on one or more attributesassociated with the selected images, said order being responsive toinput control instructions.
 13. The method of claim 5 wherein saidauxiliary image further comprises a plurality of menu areas for theselection of operations and a plurality of fields for the display ofimages from said group of selected images.
 14. The method of claim 5wherein the size and position of said frame within said auxiliary imagechanges only by steps, each step comprising a fixed number of pixels.15. A device for displaying one or more images comprisingone or moredisplay screens, an image memory for storing image data to be displayed,a control unit for converting the image data from said image memory intodevice control signals for said one or more display screens, one or moresecond memories for storing image data representing images to bedisplayed, a processing device which includes an input unit for theinput of control instructions, said processing device being configuredto perform the following operationsselecting a plurality of images forinclusion in a group of selected images from images present in said oneor more second memories, said selecting being responsive to inputcontrol instructions, writing into said image memory auxiliary imagedata representing an auxiliary image, said auxiliary image datacomprising image data representing images in said group of selectedimages at a reduced scale factor, the size of said auxiliary image onsaid one or more display screens being determined by the magnitude ofsaid group of selected images and the reduced scale factor, the positionof said auxiliary image on said one of more display screen beingresponsive to input control instructions, writing into said image memoryframe image data representing a frame, said frame being displayed withinsaid auxiliary image and having a size and position that is responsiveto input control instructions, and writing into said image memoryregular image data comprising image data representing those images ofthe part of said group of selected images that is within said frame,said regular image data being at a scale factor determined by thecombined size of the one or more display screens, the size of the partof said group of selected images within said frame, and the resolutionof the images.
 16. The device of claim 15 wherein said processing deviceis further configured to perform the following operationsaltering saidgroup of selected images either by adding additional images selectedfrom images present in said one or more second memories to the group ofselected images, or by erasing selected images from the group ofselected images, said altering according to input control instructions,and writing into said image memory altered auxiliary image datarepresenting an altered auxiliary image, said altered auxiliary imagedata comprising image data representing images in said altered group ofselected images at a reduced scale factor, the size of said alteredauxiliary image on said one or more display screens being determined bythe magnitude of said altered group of selected images and the reducedscale factor.
 17. The device of claim 15 wherein said processing deviceis further configured to perform the following operationsshifting imagedata within said auxiliary image in said image memory, said shiftedimage data representing one or more chosen images of said group ofselected images, said choosing and shifting according to input controlinstructions, and shifting in a corresponding manner image data withinsaid regular image data in said image memory, said shifted image datawithin said regular image data representing those images which wereshifted in said auxiliary image in said immediately previous shiftingoperation and which are also displayed on said one or more displayscreens.
 18. The device of claim 15 wherein said processing device isfurther configured to perform the following operationsshifting imagedata within said regular image data in said image memory, said shiftedimage data representing one or more chosen displayed images, saidshifting according to input control instruction, and shifting in acorresponding manner image data within said auxiliary image data in saidimage memory, said shifted image data within said auxiliary image datarepresenting those images which were shifted in said immediatelyprevious shifting step.
 19. The device of claim 15 wherein the imagedata comprises pixels, and wherein the processing device determinesimage data to be written into said image memory at a reduced or anincreased scale factor by averaging over pixels or by interpolatingbetween pixels, respectively.